Light emitting diode package and manufacturing method thereof

ABSTRACT

A light-emitting diode package includes a light-emitting diode chip disposed in a housing, a first phosphor configured to emit green light, and a second and a third phosphor configured to emit red light. White light is configured to be formed by a synthesis of light emitted from the light-emitting diode chip, the first phosphor, the second phosphor, and the third phosphor. At least one of the second and third phosphor is a nitride based phosphor that includes at least one of MSiN 2 , MSiON 2 , and M 2 Si 5 N 8 , where M is one of Ca, Sr, Ba, Zn, Mg, and Eu.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application is a Continuation of U.S. patent application Ser. No.16/371,774, filed on Apr. 1, 2019, which is a Continuation of U.S.patent application Ser. No. 15/645,632, filed on Jul. 10, 2017, issuedas U.S. Pat. No. 10,249,801, which is a Continuation of U.S. patentapplication Ser. No. 14/828,937, filed on Aug. 18, 2015, issued as U.S.Pat. No. 9,741,907, and claims priority from and the benefit of KoreanPatent Application No. 10-2014-0106769, filed on Aug. 18, 2014, KoreanPatent Application No. 10-2014-0112542, filed on Aug. 27, 2014, andKorean Patent Application No. 10-2015-0076499, filed on May 29, 2015,which all are hereby incorporated by reference for all purposes as iffully set forth herein.

BACKGROUND Field

Exemplary embodiments relate to a light emitting diode package and amanufacturing method of a light emitting diode package. Moreparticularly, exemplary embodiments relate to a light emitting diodepackage including a phosphor and a manufacturing method of a lightemitting diode package including a phosphor.

Discussion of the Background

A light-emitting diode (LED) package is referred to as a device thatemits light by recombining electrons and holes across a p-n junction.The LED package may have low power consumption and long lifespan and maybe manufactured in a small size compared to incandescent light.

The LED package may implement white light by using phosphor as awavelength conversion means as a yellow light-emitting phosphor, a greenlight-emitting phosphor, or a red light-emitting phosphor. However, awhite LED package using yellow light-emitting phosphor may have lowcolor rendering due to spectrum deficiency of green and red zones of theemitted light. In particular, when the white LED package is used as abacklight unit, it may be difficult to implement a natural color due tolow color purity after light is transmitted through a color filter. AnLED package using green and red light-emitting phosphors has a fullwidth at half maximum (FWHM) wider than that of the light-emitting diodechip. In particular, nitride phosphor has a wide FWHM in a redwavelength zone. The light having the wide FWHM has reduced colorreproduction. Thus, it may be difficult to implement the desired colorcoordinates in the display with a wide FWHM. Accordingly, a yellowlight-emitting phosphor, a green light-emitting phosphor, or a redlight-emitting phosphor may be unreliable.

The above information disclosed in this Background section is only forenhancement of understanding of the background of the inventive concept,and, therefore, it may contain information that does not form the priorart that is already known in this country to a person of ordinary skillin the art.

SUMMARY

Exemplary embodiments provide a light emitting diode package havingenhanced reliability and a manufacturing method thereof.

Exemplary embodiments provide a light emitting diode package including aphosphor that is stabilized against moisture and heat and amanufacturing method thereof.

Additional aspects will be set forth in the detailed description whichfollows, and, in part, will be apparent from the disclosure, or may belearned by practice of the inventive concept.

An exemplary embodiment discloses a light-emitting diode packageincluding a light emitting diode chip disposed in a housing, a firstphosphor configured to emit green light, and a second phosphorconfigured to emit red light. White light is configured to be formed bya synthesis of light emitted from the light emitting diode chip, thefirst phosphor, and the second phosphor. The second phosphor has achemical formula of A₂MF₆:Mn⁴⁺, A is one of Li, Na, K, Rb, Ce, and NH4,M is one of Si, Ti, Nb, and Ta, and Mn⁴⁺ of the second phosphor has amolar range of about 0.02 to about 0.035 times M.

The white light may have an x color coordinate and a y color coordinateforming a point present in a region on a CIE chromaticity diagram. The xcolor coordinate is about 0.25 to about 0.32 and the y color coordinateis 0.22 to 0.32.

The light-emitting diode package may include a change rate of a lightemitting intensity of the white light is about 5% or less.

A size of a peak wavelength of the green light may be about 20% to about35% of a peak wavelength of the red light.

The first phosphor may be at least one of a BAM-based phosphor and aquantum dot phosphor.

A peak wavelength of the green light of the first phosphor may include arange from about 520 nm to 570 nm. A peak wavelength of the red light ofthe second phosphor comprises a range from about 610 nm to about 650 nm.

The light emitting diode chip may include at least one of a blue lightemitting diode chip and an ultraviolet light emitting diode chip.

The white light may have a national television system committee (NTSC)color saturation which is more than or equal to about 85%.

The red light emitted from the second phosphor may have a full width athalf maximum (FWHM) less than or equal to about 15 nm.

An exemplary embodiment also discloses a light-emitting diode packageincluding a light emitting diode chip disposed in a housing, a firstphosphor configured to emit green light, and a second phosphor and athird phosphor configured to emit red light. The second phosphor has achemical formula of A₂MF₆:Mn⁴⁺, the A is one of Li, Na, K, Ba, Rb, Cs,Mg, Ca, Se, and Zn and the M is one of Ti, Si, Zr, Sn, and Ge.

The third phosphor may be a nitride-based phosphor and the red light ofthe second phosphor and the red light of the third phosphor havedifferent peak wavelengths. The third phosphor may have a mass range ofabout 0.1 wt % to about 10 wt % with respect to the second phosphor.

A first peak wavelength of the green light of the first phosphor mayinclude a first range from about 500 nm to about 570 nm. A peakwavelength of the red light of the second phosphor may include a rangefrom about 610 nm to about 650 nm. A peak wavelength of the red light ofthe third phosphor may include a range from about 600 nm to about 670nm.

The third phosphor may include at least one of MSiN₂, MSiON₂, andM₂Si₅N₈ and M is one of Ca, Sr, Ba, Zn, Mg, and Eu.

The second phosphor may have a full width at half maximum (FWHM) smallerthan that of the third phosphor.

The first phosphor may include at least one of a Ba—Al—Mg (BAM)-basedphosphor, a quantum dot phosphor, a silicate-based phosphor, abeta-SiAlON-based phosphor, a Garnet-based phosphor, and an LSN-basedphosphor.

The light emitting diode chip may include at least one of a blue lightemitting diode chip and an ultraviolet light emitting diode chip.

White light may be formed by a synthesis of light emitted from the lightemitting diode chip, the first phosphor, the second phosphor, and thethird phosphor. The white light may include a national television systemcommittee (NTSC) color saturation which is more than or equal to about85%.

The white light may include an x color coordinate and a y colorcoordinate forming a point which is present within a region on a CIEchromaticity diagram. The x color coordinate may be about 0.25 to about0.35 and the y color coordinate may be about 0.22 to about 0.32.

When a height of the housing is about 0.6 mm, the first phosphor, thesecond phosphor, and the third phosphor may have a size of about 40 μmto about 60 μm.

When a height of the housing is about 0.4 mm, the first phosphor, thesecond phosphor, and the third phosphor may have a sieve size of about15 μm to about 40 μm.

The foregoing general description and the following detailed descriptionare exemplary and explanatory and are intended to provide furtherexplanation of the claimed subject matter.

BRIEF DESCRIPTION OF THE DRAWINGS

The accompanying drawings, which are included to provide a furtherunderstanding of the inventive concept, and are incorporated in andconstitute a part of this specification, illustrate exemplaryembodiments of the inventive concept, and, together with thedescription, serve to explain principles of the inventive concept.

FIG. 1 is a cross-sectional view of an LED package according to anexemplary embodiment.

FIG. 2 is a cross-sectional view of an LED package according to anexemplary embodiment.

FIG. 3 is a cross-sectional view of an LED package according to anexemplary embodiment.

FIG. 4 is a cross-sectional view of an LED package according to anexemplary embodiment.

FIG. 5 is a cross-sectional view of an LED package according to anexemplary embodiment.

FIG. 6 is a cross-sectional view of an LED package according to anexemplary embodiment.

FIG. 7 is a cross-sectional view of an LED package according to anexemplary embodiment.

FIG. 8 is a cross-sectional view of an LED package according to anexemplary embodiment.

FIG. 9 is a cross-sectional view of an LED package according to anexemplary embodiment.

FIG. 10 is a cross-sectional view of an LED package according to anexemplary embodiment.

FIG. 11 is a flow chart of a manufacturing method of an LED packageaccording to an exemplary embodiment.

FIG. 12 is a diagram of a process of dotting a phosphor at the time ofmanufacturing the LED package according an exemplary embodiment.

FIG. 13 is a flow chart of manufacturing method of an LED packageaccording to an exemplary embodiment.

FIG. 14A a diagram of a process of dotting a molding part without aphosphor according an exemplary embodiment.

FIG. 14B is a diagram of a process of applying a phosphor plateaccording to an exemplary embodiment.

DETAILED DESCRIPTION OF THE ILLUSTRATED EMBODIMENTS

In the following description, for the purposes of explanation, numerousspecific details are set forth in order to provide a thoroughunderstanding of various exemplary embodiments. It is apparent, however,that various exemplary embodiments may be practiced without thesespecific details or with one or more equivalent arrangements. In otherinstances, well-known structures and devices are shown in block diagramform in order to avoid unnecessarily obscuring of various exemplaryembodiments.

In the accompanying figures, the size and relative sizes of layers,films, panels, regions, etc., may be exaggerated for clarity anddescriptive purposes. Also, like reference numerals denote likeelements.

When an element or layer is referred to as being “on,” “connected to,”or “coupled to” another element or layer, it may be directly on,connected to, or coupled to the other element or layer or interveningelements or layers may be present. When, however, an element or layer isreferred to as being “directly on,” “directly connected to,” or“directly coupled to” another element or layer, there are no interveningelements or layers present. For the purposes of this disclosure, “atleast one of X, Y, and Z” and “at least one selected from the groupconsisting of X, Y, and Z” may be construed as X only, Y only, Z only,or any combination of two or more of X, Y, and Z, such as, for instance,XYZ, XYY, YZ, and ZZ. As used herein, the term “and/or” includes any andall combinations of one or more of the associated listed items.

Although the terms “first,” “second,” etc. may be used herein todescribe various elements, components, regions, layers, and/or sections,these elements, components, regions, layers, and/or sections should notbe limited by these terms. These terms are used to distinguish oneelement, component, region, layer, and/or section from another element,component, region, layer, and/or section. Thus, a first element,component, region, layer, and/or section discussed below could be termeda second element, component, region, layer, and/or section withoutdeparting from the teachings of the present disclosure.

Spatially relative terms, such as “beneath,” “below,” “lower,” “above,”“upper,” and the like, may be used herein for descriptive purposes, and,thereby, to describe one element or feature's relationship to anotherelement(s) or feature(s) as illustrated in the drawings. Spatiallyrelative terms are intended to encompass different orientations of anapparatus in use, operation, and/or manufacture in addition to theorientation depicted in the drawings. For example, if the apparatus inthe drawings is turned over, elements described as “below” or “beneath”other elements or features would then be oriented “above” the otherelements or features. Thus, the exemplary term “below” can encompassboth an orientation of above and below. Furthermore, the apparatus maybe otherwise oriented (e.g., rotated 90 degrees or at otherorientations), and, as such, the spatially relative descriptors usedherein interpreted accordingly.

The terminology used herein is for the purpose of describing particularembodiments and is not intended to be limiting. As used herein, thesingular forms, “a,” “an,” and “the” are intended to include the pluralforms as well, unless the context clearly indicates otherwise. Moreover,the terms “comprises,” “comprising,” “includes,” and/or “including,”when used in this specification, specify the presence of statedfeatures, integers, steps, operations, elements, components, and/orgroups thereof, but do not preclude the presence or addition of one ormore other features, integers, steps, operations, elements, components,and/or groups thereof.

Various exemplary embodiments are described herein with reference tosectional illustrations that are schematic illustrations of idealizedexemplary embodiments and/or intermediate structures. As such,variations from the shapes of the illustrations as a result, forexample, of manufacturing techniques and/or tolerances, are to beexpected. Thus, exemplary embodiments disclosed herein should not beconstrued as limited to the particular illustrated shapes of regions,but are to include deviations in shapes that result from, for instance,manufacturing. For example, an implanted region illustrated as arectangle will, typically, have rounded or curved features and/or agradient of implant concentration at its edges rather than a binarychange from implanted to non-implanted region. Likewise, a buried regionformed by implantation may result in some implantation in the regionbetween the buried region and the surface through which the implantationtakes place. Thus, the regions illustrated in the drawings are schematicin nature and their shapes are not intended to illustrate the actualshape of a region of a device and are not intended to be limiting.

Unless otherwise defined, all terms (including technical and scientificterms) used herein have the same meaning as commonly understood by oneof ordinary skill in the art to which this disclosure is a part. Terms,such as those defined in commonly used dictionaries, should beinterpreted as having a meaning that is consistent with their meaning inthe context of the relevant art and will not be interpreted in anidealized or overly formal sense, unless expressly so defined herein.

An LED package may implement white light by using phosphor as awavelength conversion means as a yellow light-emitting phosphor, a greenlight-emitting phosphor, or a red light-emitting phosphor. Inparticular, the phosphor may be coated on an InGaN LED chip to convertsome of the primary blue light of the LED chip to secondary yellow-basedlight (e.g., yellow light or yellow-green light). The secondaryyellow-based light may mix with the primary blue light to produce whitelight. The white light-emitting diode package using a phosphor may beinexpensive and simple to manufacture.

However, a white LED package using yellow phosphor may have low colorrendering due to spectrum deficiency of green and red zones of theemitted light. In particular, when the white LED package is used as abacklight unit, it may be difficult to implement a natural color due tolow color purity after light is transmitted through a color filter.

To solve the above problem, the LED is manufactured by using the blueLED chip and phosphors emitting green light and red light by using theblue light as the excitation light. With the green and red lightemitting phosphors, it is possible to create white light having highcolor rendering by mixing the blue, green, and red light. When the whiteLED is used as a backlight unit, conformity of the white LED with thecolor filter may be very high. Thus, the white LED may implement animage closer to a natural color.

However, the light emitted by the excitation of the green and red lightemitting phosphors has a full width at half maximum (FWHM) wider thanthat of the LED chip. In particular, nitride phosphor has a wide FWHM ina red wavelength zone. The light having the wide FWHM has reduced colorreproduction. Thus, it may be difficult to implement the desired colorcoordinates in the display with a wide FWHM.

Therefore, to implement the white light having higher colorreproduction, a phosphor having a narrower FWHM may be used. To thisend, a fluoride-based phosphor is used as the phosphor emitting the redlight having the narrow FWHM. However, the fluoride-based phosphor maybe vulnerable to moisture and have reduced heat stability. A reliableLED package may be needed to apply the LED package including thephosphor to various products. The reliability of the LED packageultimately influences the reliability of products to which the lightemitting diode package is applied. Therefore, a light-emitting diodepackage including the phosphor having the high reliability while havingthe narrow FWHM may be developed.

Exemplary embodiments are discussed below that describe and illustrate awhite light LED package having higher color reproduction with a narrowerFWHM than the related art. Some exemplary embodiments may use afluoride-based phosphor not vulnerable to moisture and having reducedheat stability. Thus, the exemplary embodiments describe thelight-emitting diode packages that have high reliability with a narrowFWHM.

FIG. 1 is a cross-sectional view of an LED package according to anexemplary embodiment. Referring to FIG. 1, the LED package may include ahousing 101, an LED chip 102, a first phosphor 105, a second phosphor106, and a molding part 104.

The housing 101 may include a top surface opposite a bottom surface. Thetop surface of the housing 101 may include a lower portion, an upperportion, and an intermediate portion between the lower portion and theupper portion. The LED chip 102, the first phosphor 105, the secondphosphor 106, and the molding part 104 may be disposed on the lowerportion and the intermediate portion of the top surface of the housing101. The LED chip 102 may be disposed on the lower portion of the topsurface of the housing 101. The housing 101 may be provided with leadterminals (not illustrated) for inputting power to the LED chip 102. Themolding part 104 may include the first phosphor 105 and the secondphosphor 106. The molding part 104 may cover the LED chip 102.

The housing 101 may include at least one of a general plastic (polymer),an acrylonitrile butadiene styrene (ABS), a liquid crystalline polymer(LCP), a polyamide (PA), a polyphenylene sulfide (PPS), and athermoplastic elastomer. The housing 101 may include at least one of ametal and a ceramic. The housing 101 may also include any other suitablematerial. When the LED chip 102 is an ultraviolet LED chip, the housing101 may include ceramic. When the housing 101 is made of ceramic, thehousing 101 including ceramic is not likely to be discolored or spoileddue to ultraviolet rays that are emitted from the ultraviolet LED chip.Thus, the reliability of the light emitting diode package may bemaintained. When the housing 101 is made of metal, the housing 101 mayinclude at least two metal frames that may be insulated from each other.Thus, heat radiation performance of the LED package may be improved byincluding metal in the housing 101. Although some materials that mayform the housing 101 are described above, these materials are notexhaustive. The housing 101 may include any suitable material.

The housing 101 may include an inclined inner wall to reflect lightemitted from the light emitting diode chip 102. For example, theintermediate portion of the top surface of the housing 101 may include afirst inclined inner wall and a second inclined inner wall.

The molding part 104 may include a material selected for a desiredhardness. For example, the hardness of the molding part 104 may have ameasurement numerical value of about 65 to about 75 when being measuredby shore hardness and an indenter type may be a D type. To obtain thedesired hardness, the molding part 104 may be made of materialsincluding at least one of silicone, epoxy, polymethyl methacrylate(PMMA), polyethylene (PE), and polystyrene (PS). However, the moldingpart is not limited to these materials and may include any suitablematerial.

The molding part 104 may be formed by an injection molding process usingthe foregoing materials and a mixture of the first phosphor 105 and thesecond phosphor 106. Further, the molding part 104 may be manufacturedusing a separate mold followed by pressure or heat treatment. Themolding part 104 may be formed to have various shapes such as a convexlens shape and a flat plate shape (not illustrated). The molding part104 may also be formed to have a rough surface. Although FIG. 1illustrates the light emitting diode package including a molding part104 having the convex lens shape, it is envisioned that the molding part104 may have any suitable shape.

The LED chip 102 may be an ultraviolet light LED chip or a blue LEDchip. When the LED chip 102 is a LED chip, a peak wavelength of emittedlight may range from about 410 nm to about 490 nm. A FWHM of a peakwavelength of blue light emitted from the LED chip 102 may be less thanor equal to about 40 nm. The LED package may have a shape in which asingle LED chip 102 is disposed. However, it is envisioned that the LEDpackage may have any suitable shape and any number of LED chips 102.

The first phosphor 105 may be excited by the light emitted from the LEDchip 102 to emit green light. The second phosphor 106 may be excited bythe light emitted from the LED chip 102 to emit red light.

A peak wavelength of green light emitted from the first phosphor 105 mayrange from about 520 nm to about 570 nm. The first phosphor 105 may emitthe green light having an FWHM less than or equal to about 35 nm. Thefirst phosphor 105 may include at least one of a Ba—Al—Mg (BAM)-basedphosphor, a quantum dot phosphor, and a fluoride-based phosphor. Thefluoride-based phosphor may be a phosphor having a chemical formula ofA₂MF₆:Mn⁴⁺, with A being one of Li, Na, K, Rb, Ce, and NH₄ and M (notMn) being one of Si, Ti, Nb, and Ta. Further, the fluoride-basedphosphor may be expressed by the phosphor having a Chemical Formula ofA_(x)M_(y)F_(z):Mn⁴⁺ _(q). Here, x and z may be defined by thefollowing: 0<x≤2.5 and 0<z≤7.0. More specifically, x and z may bedefined by the following: 1.8≤x≤2.3 and 5.8≤z≤6.9. Further, q may beabout 0.02 to about 0.035 times about the y.

Although the first phosphor 105 is described above to include at leastone of a Ba—Al—Mg (BAM)-based phosphor, a quantum dot phosphor, and afluoride-based phosphor, the first phosphor 105 is not limited to suchphosphors. It is envisioned that the first phosphor 105 may include anysuitable phosphor.

As described above, the FWHM of the green light of the first phosphor105 may be narrow (e.g., less than or equal to about 35 nm). Due to thisnarrow FWHM, an LED package having high color purity may be implemented.In contrast, the FWHM of the green light of the first phosphor 105,light with a FWHM greater than or equal to about 35 nm may cause lowcolor purity of the emitted light making it difficult to reproduce acolor over 85% in a full color reproduction range defined as a standardof a national television system committee (NTSC) system. Therefore, inorder to implement NTSC color saturation of 85% or more of white lightemitted from the LED, the first phosphor 105 emits green light having aFWHM of about 35 nm or less.

The second phosphor 106 may be excited by light from the LED chip 102 toemit red light. A peak wavelength of the red light emitted from thesecond phosphor 106 may range from about 610 nm to about 650 nm. Thesecond phosphor 106 may include at least one of a quantum dot phosphor,a sulfide-based phosphor, and a fluoride-based phosphor. Thefluoride-based phosphor may be a phosphor having a chemical formula ofA₂MF₆:Mn⁴⁺. In the above chemical formula, A may be one of Li, Na, K,Rb, Ce, and NH₄ and M (not Mn) may be one of Si, Nb, Ti, and Ta.Further, the fluoride-based phosphor may be expressed by the phosphorhaving a Chemical Formula of A_(x)M_(y)F_(z):Mn⁴⁺ _(q). Here, x and ymay be defined by the following: 0<x≤2.5 and 0<z≤7.0. More specifically,x and 7 may be defined by the following: 1.8≤x≤2.3 and 5.8≤z≤6.9.Further, according to the exemplary embodiment of the present invention,q may be 0.02 to 0.035 times about the y.

The second phosphor 106 may emit red light having a narrow FWHM. Morespecifically, red light emitted from the quantum dot phosphor may havean FWHM of about 30 nm to about 40 nm. The red light emitted from thesulfide-based phosphor may have an FWHM of about 65 nm or less. The redlight emitted from the fluoride-based phosphor may have an FWHM of 20 nmor less. In other words, the red light emitted from the second phosphor106 as the fluoride-based phosphor may have the narrowest narrow FWHMcompared to the sulfide-based phosphor and the quantum dot phosphor.

Hereinafter, the case in which at least one of the first phosphor 105and the second phosphor 106 is the fluoride-based phosphor will bedescribed in more detail.

As described above, the fluoride-based phosphor may include manganese(Mn) as an active ion. As the number of moles of manganese increases, alight quantity emitted from the fluoride-based phosphor may alsoincreases. However, as the number of moles of manganese increases, themore the manganese oxidizes to form manganese oxide (MnO₂). Thus, thereliability of the phosphor and the the LED package may be reduced.

To this end, the manganese (Mn⁴⁺) in the chemical formula of A₂MF₆:Mn⁴⁺may have a number of moles within a range (i.e., a molar range) of about0.02 to about 0.035 times M. When Mn⁴⁺ has a number of moles less thanabout 0.02 times M, the LED package may have difficulty emitting asufficient amount of light. When Mn⁴⁺ has a number of moles exceedingabout 0.035 times M, the Mn⁴⁺ may increase oxidation to form moremanganese oxide than desired. Thus, the increased amount of themanganese oxide may reduce the reliability of the fluoride-basedphosphor and the LED package.

Further, when Mn⁴⁺ of the fluoride-based phosphor has a number of moleswithin the foregoing range, the LED package may minimize a change in thelight quantity. More specifically, when the LED package has the numberof moles of Mn⁴⁺ within the range of the number of moles, the change inlight quantity of the emitted white light may be about 5% or less.

Further, x and y color coordinates forming one point on a InternationalCommission on Illumination (CIE) chromaticity diagram of the white lightmay also be minimally changed. More specifically, the x colorcoordinates may be about 0.25 to about 0.32 and the y color coordinatesmay be about 0.22 to about 0.32. More specifically, the x colorcoordinates may be about 0.258 to about 0.265 and the y colorcoordinates may be about 0.225 to about 0.238.

Further, a change rate of light emitting intensity of the white lightmay also be minimal. More specifically, the change rate of the lightemitting intensity of the white light may be about 5% or less.

Hereinafter, the LED package according to an exemplary embodimentincluding the fluoride-based phosphor will be described with referenceto experiment examples.

Experimental Example 1

A first fluoride-based phosphor, a second fluoride-based phosphor, and athird fluoride-based phosphor were prepared. Here, the firstfluoride-based phosphor was expressed by a chemical formula ofK_(2.230)Si_(0.968)F_(6.870):Mn⁴⁺ _(0.032). The number of moles of Mn⁴⁺of the first fluoride-based phosphor is approximately 0.033 times theSi.

The chemical formula for the first fluoride-based phosphor is the sameas the chemical formula for the second fluoride-based phosphor and thethird fluoride-based phosphor, except for the number of moles of Mn⁴⁺and Si. The sum of the number of moles of Mn⁴⁺ and Si is maintained at 1for the second fluoride-based phosphor and the third fluoride-basedphosphor. The number of moles of Mn⁴⁺ of the second fluoride-basedphosphor is approximately 0.025 times the Si. The number of moles ofMn⁴⁺ of the third fluoride-based phosphor is approximately 0.020 timesthe Si.

A change in luminous flux, a change in luminous intensity, and a changein color coordinates of the white light of the LED package including thefluoride-based phosphors were measured. In Experimental Example 1, thefluoride-base phosphors were used as the red phosphor and one of theBAM-based phosphor (using BaMgAl₁₀O₁₇:Eu) and the quantum dot phosphor(using CdSe) was used as the green phosphor. Further, the excitationlight emitted from the LED chip had a wavelength range of about 450 nmto about 460 nm.

As a result of measuring the luminous flux, the white light of the LEDpackage (hereinafter, “first package”) including the firstfluoride-based phosphor was measured as showing a luminous flux of 74.5lm. The white light of the LED package (hereinafter, “second package”)including the second fluoride-based phosphor was measured as showing aluminous flux of 73.2 lm. The white light of the LED package(hereinafter, “third package”) including the third fluoride-basedphosphor was measured as showing a luminous flux of 72.7 lm. In otherwords, it may be appreciated that the luminous flux is changed byapproximately 1.7-2.4% depending on the change in Mn⁴⁺.

As a result of measuring the luminous intensity, the white light of thefirst package was measured as showing the luminous intensity of 23223mcd. The white light of the second package was measured as showing theluminous intensity of 22640 mcd. The white light of the third packagewas measured as showing the luminous intensity of 22491 mcd. That is, itmay be appreciated that the luminous intensity is changed byapproximately 2.5-3.2% depending on the change in Mn⁴⁺.

As a result of measuring the change in color coordinates (e.g., CIE),the x coordinate of the white light of the first package was measured as0.264 and the y coordinate of the white light of the first package wasmeasured as 0.236. The x coordinate of the white light of the secondpackage was measured as 0.264 and the y coordinate of the white light ofthe second package was measured as 0.235. The x coordinate of the whitelight of the third package was measured as 0.264 and the y coordinate ofthe white light of the third package was measured as 0.232. In otherwords, it may be appreciated that the color coordinates are minutelychanged depending on the change in Mn⁴⁺.

Further, as a comparison result that the intensity of the peakwavelength (PL intensity) of the red light included in the white lightis set to be 1, the intensity of green light of the first package may bemeasured as 0.34, the intensity of green light of the second package maybe measured as 0.27, and the intensity of green light of the thirdpackage may be measured as 0.22.

The reliability of each package for luminous intensity was tested for1000 hours. The temperature of each package was 85° C. and the currentof each package was 120 mA.

It was shown that as compared with the first intensity, the luminousintensity of the first package is reduced by 9.5%, the luminousintensity of the second package is reduced by 9.6%, and the luminousintensity of the third package is reduced by 8.8%, after 1000 hours.Further, it was shown that for the first CIE coordinates, the xcoordinate of the first package is changed by −0.013 and the ycoordinate of the first package is changed by −0.007, the x coordinateof the second package is changed by −0.014 and the y coordinate of thesecond package is changed by −0.006, and the x coordinate of the thirdpackage is changed by −0.014 and the y coordinate of the third packageis changed by −0.007.

Thus, it was shown that the luminous intensities of all of the lightemitting diode packages according to Experimental Example 1 are reducedabout 10% or less and the color coordinates are minutely changed. Bycontrast, when the luminous intensity is reduced by 10% or more and thechange in the color coordinates was large, the light emitting diodepackage may have difficulty producing light of the proper color and ofsuitably intensity. Therefore, the light emitting diode packageaccording to Experimental Example 1 may produce reliable light havingsuitable intensity and color over a long period of time.

Further, the reliability test against the luminous intensity wasadditionally performed for 1000 hours in the state in which thetemperature of each package is 60° C., relative humidity is 90%, and acurrent is 120 mA.

In this case, it was shown that as compared with the first intensity,the luminous intensity of the first package is reduced by 4.2%, theluminous intensity of the second package is reduced by 2.6%, and theluminous intensity of the third package is reduced by 3.3%. Further, itwas shown that for the first CIE coordinates, the x coordinate of thefirst package is changed by −0.006 and the y coordinate of the firstpackage is changed by −0.006, the x coordinate of the second package ischanged by −0.007 and the y coordinate of the second package is changedby −0.004, and the x coordinate of the third package is changed by−0.008 and the y coordinate of the third package is changed by −0.005.Thus, when the light emitting diode package according ExperimentalExample 1 is exposed to the high humidity environment over a long periodof time, the luminous intensity is reduced by 5% or less and the colorcoordinates are minutely changed, thereby resulting in an LED packagehaving high reliability when compared to the related art.

Experimental Example 2

A fourth fluoride-based phosphor, a fifth fluoride-based phosphor, and asixth fluoride-based phosphor were prepared. Here, the fourthfluoride-based phosphor was expressed by a chemical formula ofK_(2.130)Si_(0.970)F_(6.790):Mn⁴⁺ _(0.030). The number of moles of Mn⁴⁺of the fourth fluoride-based phosphor is approximately 0.031 times aboutSi.

The chemical formula for the fourth fluoride-based phosphor is the sameas the chemical formula for the fifth fluoride-based phosphor and thesixth fluoride-based phosphor, except for the number of moles of Mn⁴⁺and Si. The sum of the number of moles of Mn⁴⁺ and Si for the fifthfluoride-based phosphor and the sixth fluoride-based phosphor ismaintained at 1. The number of moles of Mn⁴⁺ of the fifth fluoride-basedphosphor is approximately 0.025 times about Si. The number of moles ofMn⁴⁺ of the sixth fluoride-based phosphor is approximately 0.020 timesabout Si. Here, a sum of the number of moles of Si and the number ofmoles of Mn may be maintained at 1.

A change in luminous flux, a change in luminous intensity, and a changein color coordinates, of the white light of the light emitting diodepackage including the fluoride-based phosphors were measured. InExperimental Example 2, the fluoride-base phosphors were used as a redphosphor, one of the BAM-based phosphor (used BaMgAl₁₀O₁₇:Eu) and thequantum dot phosphor (using CdSe) was used as the green phosphor.Further, the excitation light emitted from the light emitting diode chipused a wavelength range of 450 nm to 460 nm.

As a result of measuring the luminous flux, the white light of the lightemitting diode package (hereinafter, “fourth package”) including thefourth fluoride-based phosphor was measured as showing a luminous fluxof 74.4 lm, the white light of the light emitting diode package(hereinafter, “fifth package”) including the fifth fluoride-basedphosphor was measured as showing a luminous flux of 73.2 lm, and thewhite light of the light emitting diode package (hereinafter, “sixthpackage”) including the sixth fluoride-based phosphor was measured asshowing a luminous flux of 72.8 lm. In other words, it may beappreciated that the luminous flux is changed by approximately 1.6-2.2%depending on the change in Mn⁴⁺.

As a result of measuring the luminous intensity, the white light of thefourth package was measured as showing the luminous intensity of 23540mcd, the white light of the fifth package was measured as showing theluminous intensity of 22719 mcd, and the white light of the sixthpackage was measured as showing the luminous intensity of 23360 mcd. Inother words, it may be appreciated that the luminous intensity ischanged by approximately 0.8-3.5% depending on the change in Mn⁴⁺.

As a result of measuring the change in color coordinates (e.g., CIE),the x coordinate of the white light of the fourth package was measuredas 0.264 and the y coordinate of the white light of the fourth packagewas measured as 0.237, the x coordinate of the white light of the fifthpackage was measured as 0.264 and the y coordinate of the white light ofthe fourth package was measured as 0.235, and the x coordinate of thewhite light of the sixth package was measured as 0.264 and the ycoordinate of the white light of the fourth package was measured as0.234. In other words, it may be appreciated that the color coordinatesare almost constant independent of the change in Mn⁴⁺.

Further, as a comparison result that the intensity of the peakwavelength (PL intensity) of the red light included in the white lightis set to be 1, the intensity of green light of the fourth package mightbe measured as 0.32, the intensity of green light of the fifth packagemight be measured as 0.27, and the intensity of green light of the sixthpackage might be measured as 0.22.

The reliability of each package was tested for 1000 hours of theluminous intensity with a temperature of each package at 85° C. and acurrent of 120 mA.

It was shown that as compared with the first intensity, the luminousintensity of the fourth package is reduced by 8.5%, the luminousintensity of the fifth package is reduced by 9.4%, and the luminousintensity of the sixth package is reduced by 9.7%, after 1000 hours.Further, it was shown that for the first CIE coordinates, the xcoordinate of the fourth package is changed by −0.013 and the ycoordinate of the fourth package is changed by −0.007, the x coordinateof the fifth package is changed by −0.013 and the y coordinate of thefifth package is changed by −0.007, and the x coordinate of the sixthpackage is changed by −0.012 and the y coordinate of the sixth packageis changed by −0.007.

Thus, it was shown that the luminous intensities of all of the lightemitting diode packages according to Experimental Example 2 are reducedby 10% or less and the color coordinates are minutely changed. Bycontrast, when the luminous intensity is reduced by 10% or more and thechange in the color coordinates was large, the light emitting diodepackage may have difficulty producing light of the proper color and ofsuitably intensity. Therefore, the light emitting diode packageaccording to Experimental Example 2 may produce reliable light havingsuitable intensity and color over a long period of time.

Further, the reliability test against the luminous intensity wasadditionally performed for 1000 hours in the state in which thetemperature of each package is 60° C., relative humidity is 90%, and acurrent is 120 mA.

In this case, it was shown that as compared with the first intensity,the luminous intensity of the fourth package is reduced by 2.1%, theluminous intensity of the fifth package is reduced by 1.9%, and theluminous intensity of the sixth package is reduced by 2.2%. Further, itwas shown that for the first CIE coordinates, the x coordinate of thefourth package is changed by −0.007 and the y coordinate of the fourthpackage is changed by −0.004, the x coordinate of the fifth package ischanged by −0.007 and the y coordinate of the fourth package is changedby −0.004, and the x coordinate of the sixth package is changed by−0.006 and the y coordinate of the fourth package is changed by −0.005.Thus, when the light emitting diode package according to ExperimentalExample 2 is exposed to the high humidity environment over a long periodof time, the luminous intensity is reduced by 3% or less and the colorcoordinates are minutely changed, thereby securing the relatively higherreliability as compared with the related art.

According to an exemplary embodiment, the fluoride-based phosphor havingthe chemical formula A₂MF₆:Mn⁴⁺, with A being one of Li, Na, K, Rb, Ce,and NH₄, M being one of Si, Ti, Nb, and Ta, and Mn⁴⁺ of having a molarrange of about 0.02 to about 0.035 times M results in a reliable LEDpackage with sufficient light quantity.

FIG. 2 is a cross-sectional view of an LED package according to anexemplary embodiment. FIG. 2 is substantially similar to FIG. 1 exceptthat FIG. 2 may include a first phosphor 103, a second phosphor 108, anda third phosphor 107. To avoid repetition, the same elements will beomitted.

The LED chip 102, the first phosphor 103, the second phosphor 108, thethird phosphor 107, and the molding part 104 may be disposed on thelower portion and the intermediate portion of the top surface of thehousing 101 (as described with reference to FIG. 1). The molding part104 may include the first phosphor 103, the second phosphor 108, and thethird phosphor 107. The molding part 104 may cover the LED chip 102. Themolding part 104 be manufactured in the same manner as described withreference to FIG. 1 except including a mixture of the first phosphor103, the second phosphor 108, and the third phosphor 107 instead of amixture of the first phosphor 105 and the second phosphor 106. Themolding part 104 may also have the same structure and shape as describedwith reference to FIG. 1.

The first phosphor 103 may be excited by the light emitting diode chip102 to emit green light. The second phosphor 108 and the third phosphor107 may be excited by the light emitting diode chip 102 to emit redlight.

A peak wavelength of green light which is emitted from the firstphosphor 103 may range from about 500 to about 570 nm. The firstphosphor 103 may emit the green light having an FWHM less than or equalto about 35 nm. The first phosphor 103 may include at least one of aBa—Al—Mg (BAM)-based phosphor, a quantum dot phosphor, a silicate-basedphosphor, a beta-SiAlON-based phosphor, a Garnet-based phosphor, anLSN-based phosphor, and a fluoride-based phosphor. The fluoride-basedphosphor may be a phosphor having a chemical formula of A₂MF₆:Mn⁴⁺. Inthe above Chemical Formula, the A may be one of Li, Na, K, Ba, Rb, Cs,Mg, Ca, Se, and Zn and the M may be Ti, Si, Zr, Sn, and Ge. Although thefirst phosphor 103 is described above to include at least one of aBa—Al—Mg (BAM)-based phosphor, a quantum dot phosphor, a silicate-basedphosphor, a beta-SiAlON-based phosphor, a Garnet-based phosphor, anLSN-based phosphor, and a fluoride-based phosphor, the first phosphor103 is not limited to such phosphors. It is envisioned that the firstphosphor 103 may include any suitable phosphor.

The second phosphor 108 may be excited by the light emitting diode chip102 to emit red light. A peak wavelength of the red light which isemitted from the second phosphor 108 may range from about 610 to about650 nm. The second phosphor 108 may include at least one of a quantumdot phosphor, a sulfide-based phosphor, and a fluoride-based phosphor.The fluoride-based phosphor may be a phosphor having a chemical formulaof A₂MF₆:Mn⁴⁺. In the above Chemical Formula, the A may be one of Li,Na, K, Ba, Rb, Cs, Mg, Ca, Se, and Zn and the M may be one of Ti, Si,Zr, Sn, and Ge.

The second phosphor 108 may emit red light having a narrow FWHM. Morespecifically, red light emitted from the quantum dot phosphor may havean FWHM of about 30 nm to about 40 nm. The red light emitted from thesulfide-based phosphor may have an FWHM of about 65 nm or less. The redlight emitted from the fluoride-based phosphor may have an FWHM of 20 nmor less. In other words, the red light emitted from the second phosphor108 as the fluoride-based phosphor may have the narrowest FWHM comparedto the sulfide-based phosphor and the quantum dot phosphor.

The third phosphor 107 may be excited by light from the light emittingdiode chip 102 to emit red light. The peak wavelength of the red lightemitted from the third phosphor 107 may be different from that of redlight emitted from the second phosphor 108. More specifically, the peakwavelength of the red light emitted from the third phosphor 107 mayrange from about 600 nm to about 670 nm. The third phosphor 107 may be anitride-based phosphor. The nitride-based phosphor may include achemical formula expressed by MSiN₂, MSiON₂, and M₂Si₅N₈, with M beingone of Ca, Sr, Ba, Zn, Mg, and Eu. The third phosphor 107 may have amass range of 0.1 to 10 wt % with respect to the second phosphor 108. Inmore detail, the third phosphor 107 may have a mass range of 1.48 to 10wt % with respect to the second phosphor 106.

According an exemplary embodiment, when a mass percentage of the thirdphosphor 107 to the second phosphor 108 is larger than or equal to about0.1 wt %, the reliability of the phosphors may be enhanced. Further,when a mass percentage of the third phosphor 107 to the second phosphor108 is larger than or equal to about 1.48 wt %, the reliability of thephosphors may further be enhanced. Further, when the mass percentage ofthe third phosphor 107 to the second phosphor 108 exceeds 10 wt %, theFWHM of the red light emitted from the second phosphor 108 and the thirdphosphor 107 may be increased to a threshold value or more, therebyreducing the color reproduction of the LED package including the firstphosphor 103, the second phosphor 108, and the third phosphor 107. Thus,an exemplary embodiment includes a second phosphor 108 having an FWHM ina range from about 1 nm to about 10 nm and a third phosphor 107 havingan FWHM in a range from about 70 nm to 100 nm.

According an exemplary embodiment, the LED package includes the secondphosphor 108 and the third phosphor 107, both which emit red light. Whenthe third phosphor 107 is the nitride-based phosphor, the third phosphor107 is resistant to heat and/or moisture, thereby further enhance thereliability of the phosphors and the LED package. Therefore, the LEDpackage according to an exemplary embodiment may maintain the CIE colorcoordinates within a predetermined range even after a prolonged periodof use.

Hereinafter, the LED package according to an exemplary embodimentincluding the second phosphor 108 and the third phosphor 107 will bedescribed with reference to experimental examples.

Experimental Example 3

Two sample LED packages are prepared. A first sample is a red phosphorthat includes the second phosphor 108 without any other phosphor and asecond sample is a red phosphor that includes the second phosphor 108and the third phosphor 107. Except for the red phosphors (e.g., thesecond phosphor 108 without the third phosphor 107 or the secondphosphor 108 with the third phosphor 107), all other conditions of thefirst and second samples are the same.

Here, the second phosphor 108 is a fluoride-based phosphor having aChemical Formula of K₂SiF₆:Mn⁴⁺. The third phosphor 107 is anitride-based phosphor having a chemical formula of CaSiN₂:Eu²⁺. Thethird phosphor 107 has a mass of 2.96 wt % with respect to the secondphosphor 108. Each of the first and second samples includes the greenphosphor. As the green phosphor, the beta-SiAlON-based phosphor is usedand may be expressed by a chemical formula of β-SiAlON:Eu²⁺. Further, toexcite the phosphors included in each of the samples, the excited lightemitted from the LED chip 102 has a wavelength range of 440 nm to 460nm.

A reliability test was performed on each sample having the foregoingconditions for 1000 hours. A temperature of the samples was 85° C. andan input current was 20 mA.

For a first CIE coordinate after the reliability test is completed, itwas shown that an x color coordinate of the first sample is changed by−0.011 and a y color coordinate is changed by +0.002. On the other hand,it was shown that an x color coordinate of the second sample is changedby −0.007 and a y color coordinate is changed by +0.002.

Thus, it may be appreciated that an LED package according an exemplaryembodiment that includes two types of red phosphors (e.g., secondphosphor 108 and third phosphor 107) exhibits higher reliability underhigh temperature environment than an LED package that includes onefluoride-based phosphor without an additional red phosphor of adifferent type.

Experimental Example 4

The reliability test was performed for 1000 hours by changingtemperature and humidity conditions, while having the same samples asthe foregoing first and second samples of Experimental Example 3. Atemperature of the samples was 60° C., relative humidity was 90%, andthe input current was 20 mA.

For the first sample, CIE coordinates after the reliability test iscompleted, it was shown that the x color coordinate of the first sampleis changed by −0.007 and the y color coordinate is changed by +0.006. Onthe other hand, it was shown that the x color coordinate of the secondsample is changed by −0.003 and the y color coordinate is changed by+0.006.

Thus, it may be appreciated that an LED package according to anexemplary embodiment includes two types of red phosphors exhibits betterreliability under high humidity environment than a light emitting diodepackage that includes one fluoride-based phosphor without an additionalred phosphor of a different type.

FIG. 3 is a cross-sectional view of an LED package according to anexemplary embodiment. Referring to FIG. 3, the LED package includes abuffer part 109 in addition to the features illustrated and describedwith reference to FIG. 1. The features of FIG. 1 are omitted for brevityand to avoid obscuring the exemplary embodiments.

The buffer part 109 may be disposed between the LED chip 102 and themolding part 104. The buffer part may be made of materials including atleast one of silicone, epoxy, polymethyl methacrylate (PMMA),polyethylene (PE), and polystyrene (PS). The hardness of the buffer part109 may be less than that of the molding part 104. For example, thehardness of the buffer part 109 may have a measurement numerical valueof 59 to 61 when being measured by the shore hardness and the indentertype may be an A type. Thermal stress of the molding part 104 due toheat generated from the LED chip 102 may be prevented by using thebuffer part 109. Although the buffer part 109 is illustrated are beingclosely disposed around the LED chip 102, but the buffer part 109 mayalso be disposed in a wide region to contact both the first inclinedwall and the second inclined wall of the housing 101.

FIG. 4 is a cross-sectional view of an LED package according to anexemplary embodiment. Referring to FIG. 4, the LED package includes abuffer part 109 in addition to the features illustrated and describedwith reference to FIG. 2. The features of FIG. 2 are omitted for brevityand to avoid obscuring the exemplary embodiments. The buffer part 109may be the same as illustrated and described with reference to FIG. 3and thus is also omitted to avoid obscuring the exemplary embodiments.

FIG. 5 is a cross-sectional view illustrating an LED package accordingto an exemplary embodiment. Referring to FIG. 5, the LED packageincludes a reflector 111 and a barrier reflector 112 in addition to thefeatures illustrated and describe with reference to FIG. 1. The featuresof FIG. 1 are omitted for brevity and to avoid obscuring the exemplaryembodiments.

The reflector 111 may be disposed on a side of the housing 101, whilebeing spaced apart from the LED chip 102. For example, the reflector 111may be disposed on the first inclined wall and the second inclined wallof the housing 101. The reflector 111 may be configured to maximize thereflection of light emitted from the LED chip 102 and the first phosphor105 and the second phosphor 106 to increase luminous efficiency. Thereflector 111 may be formed of any one of a reflection coating film anda reflection coating material layer. The reflector 111 may include atleast one of inorganic materials and organic materials. The reflectormay include have excellent heat resistance and light resistance such asmetals and metal oxides. For example, the reflector 111 may include atleast one of aluminum (Al), silver (Ag), gold (Au), and titanium dioxide(TiO₂). The reflector 111 may be formed by depositing or coating themetals or the metal oxides on the housing 101. The reflector 111 mayalso be formed by printing metal ink. Further, the reflector 111 mayalso be formed by bonding a reflection film or a reflection sheet on thehousing 101. The reflector 111 is not limited to the materials listedand may include any suitable material. In addition, the reflector may beformed by any suitable means.

The barrier reflector 112 may cover the reflector 111. The barrierreflector 112 may prevent the deterioration of the reflector 111 due tothe heat emitted from the LED chip 102. The barrier reflector 112 mayinclude at least one of organic materials and inorganic materials. Thebarrier reflector 112 may include metal materials having the high lightresistance and reflectance.

FIG. 6 is a cross-sectional view of an LED package according to anexemplary embodiment. Referring to FIG. 6, the LED package includes thereflector 111 and barrier reflector 112 described with reference to FIG.5 in addition to the features illustrated and described with referenceto FIG. 2. The similar features of FIG. 2 and FIG. 5 are omitted forbrevity and to avoid obscuring the exemplary embodiments.

FIG. 7 is a cross-sectional view of an LED package according to anexemplary embodiment. Referring to FIG. 7, the LED package includes amolding part 104 that includes a first molding part 104 b and a secondmolding part 104 a in addition to the features described and illustratedwith respect to FIG. 1. The similar features of FIG. 1 are omitted forbrevity and to avoid obscuring the exemplary embodiments.

The first molding part 104 b may cover the LED chip 102. The secondmolding part 104 a may cover the first molding part 104 b. The firstmolding part 104 b may include the same or different material as thesecond molding part 104 a. The first molding part 104 b may have thesame or a different hardness as the second molding part 104 a. Thehardness of the first molding part 104 b may be lower than the hardnessof the second molding part 104 a. Similar to the buffer part 109, whenthe hardness of the first molding part 104 b is lower than the secondmolding part 104 a, thermal stress due to the heat from the LED chip 102may be alleviated.

The first molding part 104 b may include the second phosphor 106 whichemits the red light. The second molding part 104 a may include the firstphosphor 105 which emits the green light. Thus, the phosphors that emitlong wavelength light are disposed closer to the LED chip 102 that(i.e., at a lower portion in the LED package) than the phosphors thatemit short wavelength light. Accordingly, the arrangement of thephosphors prevents the second phosphors 106 from absorbing the greenlight emitted from the first phosphor 105.

FIG. 8 is a cross-sectional view of a light emitting diode packageaccording to an eighth exemplary embodiment of the present invention.Referring to FIG. 8, the LED package includes a molding part 104 thatincludes a first molding part 104 b and a second molding part 104 a inaddition to the features described and illustrated with respect toFIG. 1. The similar features of FIG. 2 are omitted for brevity and toavoid obscuring the exemplary embodiments. The first molding part 104 bof FIG. 8 is the same as the first molding part 104 b described andillustrated with reference to FIG. 7, except the first molding part 104b of FIG. 8 includes the second phosphor 108 and the third phosphor 107described with reference to FIG. 2. The second molding part 104 a is thesame as the second molding part 104 a described and illustrated withreference to FIG. 7, except the second molding part 104 a of FIG. 8includes the first phosphor 103 described with reference to FIG. 2

Similar to FIG. 7, the phosphors of FIG. 8 that emit a long wavelengthare disposed closer to the LED chip 102 that (i.e., at a lower portionin the LED package) than the phosphors that emit short wavelength light.In other words, the second phosphors 108 and the third phosphors 107 aredisposed closer to the LED chip 102 than the first phosphors 103.Accordingly, the arrangement of the phosphors prevents the secondphosphors 108 and the third phosphors 107 from absorbing the green lightemitted from the first phosphors 103.

FIG. 9 is a cross-sectional view of an LED package according to anexemplary embodiment. Referring to FIG. 9, the LED package may includeall the features described with references to FIG. 1, except FIG. 9 alsoincludes a phosphor plate 118 with a first phosphor 105 and a secondphosphor 106 and a molding part 104 without the first phosphor 105 andthe second phosphor 106. The similar features of FIG. 1 are omitted forbrevity and to avoid obscuring the exemplary embodiments.

Referring to FIG. 9, the phosphor plate 118 may be disposed on themolding part 104 while being spaced apart from the LED chip 102. Thephosphor plate 118 may include the first phosphor 105 and the secondphosphor 106. The phosphor plate 118 may include the same material asthe molding part 104. Alternately, the phosphor plate 118 may include aharder material than the molding part 104. In an alternate embodiment,an empty space may be formed between the phosphor plate 118 and thelight emitting diode chip 102 instead of the molding part 104.

Because the first phosphor 105 and the second phosphor 106 are disposedwhile being spaced from the light emitting diode chip 102, it ispossible to reduce damage to the first phosphor 105 and the secondphosphor 106 and the phosphor plate 118 caused by heat or light from thefirst phosphor 105 and the second phosphor 106 first and secondphosphors 105 and 106. In addition, damage to the first phosphor 105 andthe second phosphor 106 from the heat generated from the LED chip 102may be reduced by using the phosphor plate 118 that is space apart fromthe LED chip 102. Therefore, the reliability of the first phosphor 105and the second phosphor 106 may be improved.

According to an exemplary embodiment, it is possible to provide the LEDpackage including the phosphor emitting light having the narrow FWHM toimprove the color reproduction of the LED package. Further, it ispossible to prevent the deterioration phenomenon of the phosphor underthe high temperature and/or high humidity environment to improve thereliability of the phosphor, thereby improving the overall reliabilityof the LED package.

FIG. 10 is a cross-sectional view of a LED package according to anexemplary embodiment. Referring to FIG. 10, the LED package may includeall the features described with references to FIG. 2, except FIG. 10also includes a phosphor plate 118 with a first phosphor 103, a secondphosphor 108, a third phosphor 107, and a molding part 104 without thefirst phosphor 103, the second phosphor 108, the third phosphor 107. Thesimilar features of FIG. 2 are omitted for brevity and to avoidobscuring the exemplary embodiments.

Referring to FIG. 10, the phosphor plate 118 may be disposed on themolding part 104 while being spaced apart from the light emitting diodechip 102. The phosphor plate 118 may include the first phosphor 103, thesecond phosphor 108, and the third phosphor 107. The phosphor plate 118may include the same material as the molding part 104. Alternately, thephosphor plate 118 may include a harder material than the molding part104. In an alternate embodiment, an empty space may be formed betweenthe phosphor plate 118 and the light emitting diode chip 102 instead ofthe molding part 104.

Because the first phosphor 103, second phosphor 108, and the thirdphosphor 107 are disposed while being spaced from the light emittingdiode chip 102, it is possible to reduce damage to the first phosphor103, second phosphor 108, and the third phosphor 107 caused by heat orlight from the first phosphor 103, second phosphor 108, and the thirdphosphor 107. In addition, damage to the first phosphor 103, secondphosphor 108, and the third phosphor 107 from the heat generated fromthe LED chip 102 may be reduced by using the phosphor plate 118 that isspace apart from the LED chip 102. Therefore, the reliability of thefirst phosphor 103, second phosphor 108, and the third phosphor 107 maybe improved.

FIG. 11 is a flow chart of a manufacturing method 1100 of an LED packageaccording to an exemplary embodiment. FIG. 12 is a diagram illustratinga process of dotting phosphors 103, 108, and 107 at the time ofmanufacturing the LED package according to an exemplary embodiment. Themanufacturing method 1100 of the LED package according to an exemplaryembodiment will be described with reference to FIG. 12 along with theflow chart of FIG. 11.

According to an exemplary embodiment, the method 1100 includesmanufacturing a lead frame (S101). The lead frame may form a conductivepattern on a surface of a substrate. Further, the manufacturingprocesses may alter the shape of the lead frame based on the type of theLED package.

The method 1100 may further include mounting the LED chip 102 to thelead frame (S102). Specifically, the LED chip 102 may be mounted on theconductive pattern formed on the lead frame. The lead frame is not shownin FIG. 12.

The method 1100 may further include forming the housing 101 (S103 a).The housing 101 may be form (or packaged) such that the LED chip 102 ismounted on the lead frame. As illustrated in FIG. 12, the housing 101may be formed to enclose a part or the entire lead frame to support thelead frame. The housing 101 may also be formed such that it includes acavity with the LED chip disposed in that cavity.

The method 1100 may optionally include forming a buffer part 109 (S103b). The buffer part 109 may be formed in any suitable manner. Forexample, the buffer part 109 may be formed by disposing the buffer part109 over the LED chip 102 and a portion of the housing 101 immediatelysurrounding the LED chip 102. The buffer part 109 may be applied to theLED chip 102 and the housing 101 with the needle 200 in a similarfashion as the molding part 104. For example, the buffer part may beapplied over the LED chip 102 and a portion of the housing 101immediately surrounding the LED chip 102 with the needle 200 or someother injection type device and the subsequently cure with at least oneof heat, ultra violet light, and pressure. The buffer part 109 may beprinted over the LED chip 102.

The molding part 104 needs to be manufactured before the molding part104 is formed in the formed housing 101. Although FIG. 12 illustratesthe first phosphor 103, the second phosphor 108, and the third phosphor107 forming the molding part 104, it is envisioned that the molding partmay include at least one of the first phosphor 105, the first phosphor103, the second phosphor 106, the second phosphor 108, and the thirdphosphor 107 described in the above exemplary embodiment. For clarityand ease of reference in describing the manufacturing method, themolding part 104 will be described as having the first phosphor 103, thesecond phosphor 108, and the third phosphor 107. However, themanufacturing method is not intended to be limited to the first phosphor103, the second phosphor 108, and the third phosphor 107 forming themolding part 104. The light emitted from the LED chip 102 is excited byat least one of the phosphors 107, 103, and 108 having a grain shape anda predetermined size as illustrated in FIG. 12. The phosphors 107, 103,and 108 having a granular particle shape are formed in the LED packagein the state in which they are mixed in the liquid-phase molding part104.

When the molding part 104 is formed on the upper portion of the lightemitting diode chip 102, the molding part 104 may be formed by variousprocesses, but it will be described that the molding part is formed bythe dotting process in the manufacturing method of a LED packageaccording to an exemplary embodiment.

The dotting process applies the liquid-phase molding part 104 using aneedle 200 to the upper portion of the LED chip 102. To accommodatevarieties in LED package sizes, an inlet of the needle 200 may alsovary. The phosphors 107, 103, and 108 having the granular particle shapemay be mixed with the liquid-phase molding part 104. The mixture may bedotted on the LED package using the needle 200. If the particles of thephosphors 107, 103, and 108 are larger than the inlet of the needle 200,the inlet of the needle 200 may become plugged. For this reason, theparticle size of the phosphors 105, 106, and 107 needs to be limiteddepending on the size of the LED package. According to an exemplaryembodiment, the phosphors 107, 103, and 108 may be sieved depending onthe required size prior to manufacturing the liquid-phase molding part104.

The method 1100 may further include sieving the phosphors 107, 103, and108 (S104 a). The sieving of the phosphors 107, 103, and 108 is aprocess of filtering the phosphors 107, 103, and 108 to allow the sizeof the phosphors 107, 103, and 108 to refrain from exceeding apredetermined size (i.e., a small enough size to prevent the needle 200from plugging due to the phosphors). According to an exemplaryembodiment, when the entire height of the housing 101 is 0.6 mm, thephosphors 103, 108, and 107 may have a mesh size of about 40 μm to about60 μm. As a further example, the mesh size of the phosphors 103, 108,and 107 used with a housing of about 0.6 mm may be about 40 μm to about50 μm. Further, when the entire height of the housing 101 is 0.4 mm, thephosphors 103, 108, and 107 may have a mesh size of about 15 μm to about40 μm. As a further example, the mesh size of the phosphors 103, 108,and 107 used with a housing of about 0.4 mm may be about 25 μm to 35 μm.

The method 1100 may optionally include forming the barrier reflector 112may be formed on the housing 101 (S104 b). For example, forming thebarrier reflector 112 may include disposing the barrier reflector 112using any suitable method such as depositing, coating, and/or printing amaterial (e.g., a metal, a metal oxide) on the housing 101. Further, thebarrier reflector 112 may also be formed by bonding a film or a sheet onthe housing 101. In addition, the barrier reflector 112 may be formed byany other suitable means. The barrier reflector 112 may be formed on aside of the housing 101 while being spaced apart from the LED chip 102.T

The method 1100 may optionally include forming a reflector 111 (S104 c).The reflector 111 may be formed over the barrier reflector 112. Formingthe reflector may include similar means as described with respect to thebarrier reflector 112.

The method 1100 may include mixing the sieved phosphors 107, 103, and108 in the liquid-phase molding part 104 to manufacture the liquid-phasemolding part 104 (S105). The molding part 104 may include variousmaterials such as a resin, a hardener, or other additives in addition tothe phosphors 107, 103, and 108 to form the molding part 104. Forexample, the molding part 104 may include at least one of silicone,epoxy, polymethyl methacrylate (PMMA), polyethylene (PE), andpolystyrene (PS) in addition to the phosphors 107, 103, and 108.

Although the molding part 104 illustrated in FIG. 12 shows phosphors103, 108, and 107, the molding part 104 may include phosphors 105 and106. The first phosphor 105 may have the peak wavelength of the greenlight ranging from about 520 nm to about 570 nm and the first phosphor103 may have the peak wavelength of the green light ranging from about500 nm to about 570 nm. The second phosphors 106 may each have the peakwavelength of the red light ranging from about 610 nm to about 650 nm.Further, the third phosphor 107 may have the peak wavelength of the redlight ranging from about 600 nm to about 670 nm.

As described above, as the particle size of the phosphor is limited, theparticle size of the phosphor may be constant at a predetermined size.The light emitted from the LED chip 102 may be excited by phosphors(e.g., phosphors 105, 106, 107, 103, and 108) having the uniformparticle size, thus a color coordinate distribution of light may bereduced such that the light emitted from the LED package according to anexemplary embodiment of the may have uniform quality. Further, the inletof the needle 200 does not clog when dotting the liquid-phase moldingpart 104 with phosphors (e.g., phosphors 105, 106, 107, 103, and 108) ofa uniform particle size at or below a predetermined size on the housing101.

The method 1100 may also include dotting the manufactured liquid-phasemolding part 104 on the housing 101 of the LED package using the needle200 (S106). In this case, as described in other exemplary embodiments,the molding part 104 may be formed to have various shapes.

The method 1100 may further include curing the liquid-phase molding part104 is hardened (S107). The liquid-phase molding part 104 may be curedby a variety of processes. For example, the liquid-phase molding partmay be subjected to at least one of a pressure treatment, a heattreatment, and ultra violet light treatment. The manufactured LEDpackage may be subjected a post-process (e.g., operability testing andreliability testing).

The method illustrated and describe with respect to FIGS. 11 and 12 maybe applied to any of the embodiments describes with respect to FIGS.1-10 without limitation. Although FIG. 12 and the associated descriptionof FIGS. 11 and 12 describe sieving phosphor and forming a singlemolding part 104, the steps S104 a, S105, S106, and S107 of method 1100may include sieving phosphor and forming a first molding part 104 b andsecond molding part 104 a as described with respect to FIGS. 7 and 8.With respect to the exemplary embodiment described with reference toFIG. 7, second phosphors 106 may be sieved for the first molding part104 b following by manufacturing the first molding part 104 b, dottingthe first molding part 104 b, and curing the first molding part 104 bfor the respective steps S104 a, S105, S106, and S107 of method 1100.Then, the steps S104 a, S105, S106, and S107 of method 1100 may berepeated for sieving first phosphors 105 for the second molding part 104a, manufacturing the second molding part 104 a, dotting the secondmolding part 104 a, and curing the second molding part 104 a.

Similarly, with respect to the exemplary embodiment described withreference to FIG. 8, second phosphors 108 and third phosphor 107 may besieved for the first molding part 104 b following by manufacturing thefirst molding part 104 b, dotting the first molding part 104 b, andcuring the first molding part 104 b for the respective steps S104 a,S105, S106, and S107 of method 1100. Then, the steps S104 a, S105, S106,and S107 of method 1100 may be repeated for sieving first phosphors 103for the second molding part 104 a, manufacturing the second molding part104 a, dotting the second molding part 104 a, and curing the secondmolding part 104 a. The first molding part 104 b and the second moldingpart 104 a may be cured at the same time. It is envisioned that thefirst molding part 104 b and the second molding part 104 a may be curedat the same time for either modification.

FIG. 13 is a flow chart of a manufacturing method 1300 of an LED packageaccording to an exemplary embodiment. FIG. 14A is a diagram illustratinga process of dotting a molding part 104 according to an exemplaryembodiment. FIG. 14B is a diagram illustrating a process of applying aphosphor plate 118 according to an exemplary embodiment. Themanufacturing method 1300 of the LED package according to an exemplaryembodiment will be described with reference to FIGS. 14A and 14B alongwith the flow chart of FIG. 13.

The manufacturing method 1300 includes the steps of manufacturing thelead frame (S201), mounting the LED chip 102 to the lead frame (S202),forming a housing 101 (S203), sieving phosphors (S204), forming aphosphor plate 118 (S208). The manufacturing method 1300 may alsooptionally include manufacturing a molding part 104 (S205), dotting themolding part 104 (S106), and curing the molding part 104 (S207). StepsS201, S202, S203, S204 of method 1300 are substantially similar to therespective steps S101, S102, S103 a, and S104 a of method 1100. StepsS205, S206, S207 of method 1300 are substantially similar to the stepsof S105, S106, and S107 of method 1100, except steps S205, S206 and S207are optional steps. These similarities in the steps are also not furtherdescribed to avoid obscuring exemplary embodiment.

The method 1300 may optionally include manufacturing a liquid-phasemolding part 104 without phosphors (S205). Thus, manufacturing theliquid-phase molding part 104 may be the same as that with reference tomethod 1100 except that the phosphors are mixed not with liquid-phasemolding part 104 in method 1300. These similarities are also not furtherdescribed to avoid obscuring exemplary embodiment.

The method 1300 may optionally include dotting the liquid-phase moldingpart 104 without phosphors (S206). As shown in FIG. 14A, the needle 200described with reference to FIG. 12 may be used for this process. StepS206 may be substantially similar to step S106. These similarities arealso not further described to avoid obscuring exemplary embodiment.

The method 1300 may optionally include curing the molding part 104(S207). Step S207 may be substantially similar to step S107. Thesesimilarities are also not further described to avoid obscuring exemplaryembodiment.

The method 1300 may further include forming the phosphor plate 118(S208). As shown in FIG. 14B, forming the phosphor plate 118 may includemixing the sieved phosphors 107, 103, and 108 in a liquid-phase phosphorplate 118. Although not shown, forming the phosphor plate 118 mayinclude mixing the sieved phosphors 105 and 106 in a liquid-phasephosphor plate 118. The phosphor plate 118 may include the same materialas the molding part 104. The phosphor plate 118 may include a resin, ahardener, or other additives in addition to the phosphors 107, 103, and108. For example, the molding part 104 may include at least one ofsilicone, epoxy, polymethyl methacrylate (PMMA), polyethylene (PE), andpolystyrene (PS) in addition to the phosphors 107, 103, and 108.

The phosphor plate 118 may be applied by dotting with the needle 200shown with in FIG. 14a . The phosphor plate 118 may also be curedsimilar to the molding part 104. Alternatively, the phosphor plate 118may partially or fully cure prior to being disposed on the LED package.In that case the phosphor plate 118 may be applied using a mechanicalarm 130 or some other tool to align the partially cured or fully curedphosphor plate 118.

According to exemplary embodiments, it is possible to provide an LEDpackage including the phosphor emitting light having the narrow FWHM toimprove the color reproduction of the LED package. Further, it ispossible to prevent the deterioration phenomenon of the phosphor due toa high temperature and/or a high humidity environment, thereby improvingthe reliability of the phosphor and the LED package compared to therelated art.

According to exemplary embodiments, the reliability of the phosphorincluded in the LED package may be enhanced also resulting in thereliability of the LED package being enhanced. Therefore, it is possibleto minimize the change in CIE color coordinates and maintain lightemitted from an LED package over a prolonged long period when comparedto the related art.

According to exemplary embodiments, the phosphor included in the LEDpackage may emit the green light and/or the red light having the narrowFWHM thereby enhancing the color reproduction of the LED package whencompared to the related art.

Although certain exemplary embodiments and implementations have beendescribed herein, other embodiments and modifications will be apparentfrom this description. Accordingly, the inventive concept is not limitedto such embodiments, but rather to the broader scope of the presentedclaims and various obvious modifications and equivalent arrangements.

What is claimed is:
 1. A light-emitting diode package, comprising: ahousing including a top surface opposite a bottom surface; alight-emitting diode chip disposed in the housing; a first phosphorconfigured to emit green light; a second phosphor configured to emit afirst red light; and a third phosphor configured to emit a second redlight, wherein: the top surface of the housing include a lower portion,an upper portion and an intermediate portion between the lower portionand the upper portion, the light-emitting diode chip has a Full Width atHalf Maximum (FWHM) less than or equal to about 40 nm, the first,second, and third phosphors are disposed in a molding part and themolding part is made of materials including at least one of silicone,epoxy, polymethylmethacrylate (PMMA), polyethylene (PE) and polystyrene(PS), a peak wavelength of the first phosphor ranges from about 520 nmto 570 nm, at least one of the second and third phosphors is anitride-based phosphor, the first red light emitted from the secondphosphor and the second red light emitted from the third phosphor havedifferent peak wavelengths in which one of the different peakwavelengths ranges from about 610 nm to about 650 nm and the otherdifferent peak wavelength ranges from about 600 nm to 670 nm, at leastone of the first, second, and third phosphors has a different Full Widthat Half Maximum (FWHM) from the other of the first, second, and thirdphosphors, and a white light is configured to be formed by a synthesisof light emitted from the light-emitting diode chip, the first phosphor,the second phosphor and the third phosphor.
 2. The light-emitting diodepackage of claim 1, wherein an intensity of a peak wavelength of thegreen light is smaller than a maximum intensity of the first or secondred light.
 3. The light-emitting diode package of claim 1, wherein thenitride based phosphor includes at least one of MSiN₂, MSiON₂, andM₂Si₅N₈ and M is one of Ca, Sr, Ba, Zn, Mg, and Eu.
 4. Thelight-emitting diode package of claim 1, wherein the light-emittingdiode package comprises a plurality of LED chips.
 5. The light-emittingdiode package of claim 1, wherein the light-emitting diode chip emitslight of a peak wavelength between 410 nm and 490 nm.
 6. Thelight-emitting diode package of claim 1, wherein the light-emittingdiode chip emits light of a peak wavelength between 440 nm to 460 nm. 7.The light-emitting diode package of claim 1, wherein one of the secondand third phosphors has a mass range of about 0.1 wt % to about 10 wt %with respect to the other of the second and third phosphors.
 8. Alight-emitting diode package, comprising: a housing including a topsurface opposite a bottom surface; a light-emitting diode chip disposedin the housing; a first phosphor configured to emit green light; asecond phosphor configured to emit a first red light; and a thirdphosphor configured to emit a second red light, wherein: the top surfaceof the housing include a lower portion, an upper portion and anintermediate portion between the lower portion and the upper portion,the first, second, and third phosphors are disposed in a molding partand the molding part is made of materials including at least one ofsilicone, epoxy, polymethylmethacrylate (PMMA), polyethylene (PE) andpolystyrene (PS), the light-emitting diode chip has a Full Width at HalfMaximum (FWHM) less than or equal to about 40 nm, is a peak wavelengthof the first phosphor ranges from about 520 nm to 570 nm, at least oneof the second and third phosphors is a nitride-based phosphor, the firstred light emitted from the second phosphor and the second red lightemitted from the third phosphor have different peak wavelengths in whichone of the different peak wavelengths ranges from about 610 nm to about650 nm and the other different peak wavelength ranges from about 600 nmto 670 nm, at least one of the first, second, and third phosphors has aFull Width at Half Maximum (FWHM) wider than that of the light-emittingdiode chip, and a white light is configured to be formed by a synthesisof light emitted from the light-emitting diode chip, the first phosphor,the second phosphor, and the third phosphor.
 9. The light-emitting diodepackage of claim 8, wherein an intensity of a peak wavelength of thegreen light is smaller than a maximum intensity of the first or secondred light.
 10. The light-emitting diode package of claim 8, wherein thenitride based phosphor includes at least one of MSiN₂, MSiON₂, andM₂Si₅N₈ and M is one of Ca, Sr, Ba, Zn, Mg, and Eu.
 11. Thelight-emitting diode package of claim 8, wherein the light-emittingdiode package comprises a plurality of LED chips.
 12. The light-emittingdiode package of claim 8, wherein the light-emitting diode chip emitslight of a peak wavelength between 410 nm and 490 nm.
 13. Thelight-emitting diode package of claim 8, wherein the light-emittingdiode chip emits light of a peak wavelength between 440 nm to 460 nm.14. The light-emitting diode package of claim 8, wherein one of thesecond and third phosphors has a mass range of about 0.1 wt % to about10 wt % with respect to the other of the second and third phosphors. 15.A light-emitting diode package, comprising: a housing including a topsurface opposite a bottom surface; a light-emitting diode chip disposedin the housing; a first phosphor configured to emit green light; and asecond phosphor configured to emit red light, wherein: the top surfaceof the housing include a lower portion, an upper portion and anintermediate portion between the lower portion and the upper portion,the light-emitting diode chip has a Full Width at Half Maximum (FWHM)less than or equal to about 40 nm, the first and second phosphors aredisposed in a molding part and the molding part is made of materialsincluding at least one of silicone, epoxy, polymethylmethacrylate(PMMA), polyethylene (PE) and polystyrene (PS), a peak wavelength of thefirst phosphor ranges from about 520 nm to 570 nm, a peak wavelength ofthe second phosphor ranges from about 600 nm to 670 nm, the secondphosphor is a nitride-based phosphor and has a Full Width at HalfMaximum (FWHM) different from the first phosphor, at least one of thefirst and seconds phosphors has a Full Width at Half Maximum (FWHM)wider than that of the light-emitting diode chip, and a white light isconfigured to be formed by a synthesis of light emitted from thelight-emitting diode chip, the first phosphor, and the second phosphor.16. The light-emitting diode package of claim 15, wherein an intensityof a peak wavelength of the green light is smaller than a maximumintensity of the red light.
 17. The light-emitting diode package ofclaim 15, wherein the light-emitting diode package comprises a pluralityof LED chips.
 18. The light-emitting diode package of claim 15, whereinthe light-emitting diode chip emits light of a peak wavelength between410 nm and 490 nm.
 19. The light-emitting diode package of claim 15,wherein the light-emitting diode chip emits light of a peak wavelengthbetween 440 nm to 460 nm.
 20. The light-emitting diode package of claim15, further comprising a third phosphor configured to emit a second redlight, wherein one of the second and third phosphors has a mass range ofabout 0.1 wt % to about 10 wt % with respect to the other of the secondand third phosphors.